Is this yet another instance of me falling into something because it has the word "bug" in the name? Well, actually no. One of the things that made Fitbug so good to use was that it only required small changes in lifestyle in order to make a difference. It works on the concept of energy in versus energy out. Using the Bug to record activity, the website to record additional activity, food intake and weight, it determines whether you're taking in more energy than you're expending. It then uses this information, once it's built up a profile of your activity and food intake, to set you targets based on what you want to achieve.
For me, weight loss is secondary to how I feel. I want to feel (and be) fit and healthy. I believe that this is a big part of making it towards that. If I lose weight along the way, then all well and good.